Compatible Microgreen Seeds for Reusable Grow Mediums: Complete Guide

January 23, 2026

One of the most common questions we receive at On The Grow is about seed compatibility with reusable grow mediums. Not every microgreen seed behaves the same when grown hydroponically, and understanding these differences can save you time, money, and frustration.

After extensive testing with 70+ microgreen varieties, we've created this comprehensive guide to help you choose the right seeds for your reusable grow medium setup. New to microgreens entirely? Start with our beginner's guide to growing microgreens or grab our Beginner's Guide PDF.

Quick Answer: Which Seeds Work on Reusable Grow Mediums?

Most medium to large seeds with manageable root systems grow exceptionally well on reusable silicone grow mediums, including broccoli, radish, kale, cabbage, mustard, sunflower, basil, and arugula. Peas grow best directly on a bare mesh tray with NO medium since their aggressive roots tangle deeply into any medium. Very fine seeds like amaranth, celosia, and red-veined sorrel were previously thought to fall through the mesh, but we've confirmed they grow successfully on our 1.2mm silicone when using a heat mat at 75°F during germination. Beets, Swiss chard, cilantro, fennel, buckwheat, borage, nasturtium, and marigold all prefer soil or coco coir.

What Determines Seed Compatibility?

Three main factors influence whether a microgreen seed will grow well on a reusable grow medium:

Seed Size. Medium to large seeds typically perform better because they sit securely on the mesh without falling through the holes. Our 1.2mm standard silicone reusable grow medium works for most varieties, while the 1.7mm large-hole silicone is designed for larger seeds and aggressive root systems.

Root Behavior. Seeds with manageable root systems are easier to harvest and clean up after. Some varieties (like peas) develop aggressive roots that can tangle deeply into the medium.

Germination Preferences. Certain seeds simply prefer the moisture retention and support that soil or coco coir provides, making them better suited for traditional growing methods.

If you're new to reusable grow mediums, head over to our full reusable silicone grow medium guide for everything we know about the product itself, including specs, certifications, and care.

Broccoli microgreens sprouting on On The Grow's reusable silicone grow medium

Seeds That Work Exceptionally Well

These varieties have consistently performed well on our reusable silicone grow medium. They feature medium to large seeds with manageable root systems that make cleanup straightforward.

Broccoli Varieties

Waltham 29, Di Cicco, Purple Sprouting, Calabrese Green, and Ramoso Santana all excel on reusable grow mediums. Broccoli is an excellent choice for beginners because it germinates reliably and harvests cleanly. For a full grow walkthrough, see our how to grow broccoli microgreens blog.

Radish Varieties

Rambo, Daikon Minowase, China Rose, Triton Purple, Sango Purple, Red Arrow, Purple Plum, Hong Vit, Purple, Colorful Radish, and Confetti Mix are all strong performers. Radish microgreens grow quickly and their roots release easily from the medium.

Kale Varieties

Red Russian, Vates Blue Scotch Curled, Black Tuscan (Lacinato), Dwarf Siberian, White Russian, Bright Green Curly, Purple Reign, KX-1, Unicorn, Kalefetti Mix, and Red Kale varieties all work beautifully. Kale produces dense, nutrient-rich microgreens with minimal root entanglement.

Cabbage and Pak Choi

Red Acre, Mammoth Red Rock, Golden Acre, Glory of Enkhuizen, Pak Choi White Stem, and Red Pak Choi are reliable choices that grow well hydroponically on mesh surfaces.

Mustard and Asian Greens

Spicy Oriental, Mizuna, Mizuna Red, Tatsoi, Red Tatsoi, Komatsuna (Spinach Mustard), and Mizuna Red Kingdom offer bold flavors and consistent performance.

Other Brassicas

Kohlrabi Purple Vienna, Kohlrabi Early White Vienna, Brussels Sprouts Long Island Improved, Turnip Purple Top White Globe, Rutabaga American Purple Top, Collards Vates, Cauliflower Snowball Y Improved, and Cauliflower Igloo round out the brassica family with excellent compatibility.

Basil Varieties

Genovese, Italian Large Leaf, Dark Opal, Bicolor, Colorful Basil Mix, and Lemon Basil grow well on reusable grow mediums and develop robust flavor profiles. Tip: Basil is mucilaginous (forms a gel coating when wet), so spread the seeds DRY on the medium and mist lightly on top. Never soak basil seeds before planting.

Additional Compatible Varieties

Arugula Slow Bolt, Arugula Astro, Curled Cress, Fenugreek, Purslane, Red Gruner, Chia, Red Clover, and Crimson Clover all perform well with proper watering techniques. Note that arugula and chia are also mucilaginous, so the same dry-seeding rule applies.

Seed Mixes

Basic Salad Mix, Spicy Salad Mix, Mild Micro Mix, and Superfood Mix are pre-blended options that work reliably on reusable grow mediums.

Sunflower

Black Oil Sunflower is a popular choice that works exceptionally well, especially when using our 1.7mm large-hole silicone medium designed specifically for larger seeds. Always rinse sunflower seeds before planting. Sunflower works on both the 1.2mm and 1.7mm silicone.

You can buy any of these recommended seed varieties from True Leaf Market, our trusted seed source.

Seeds That Work Better Without a Medium

Some varieties technically can grow on reusable grow mediums, but they perform significantly better when grown directly on a mesh tray without any medium underneath.

Pea Varieties

Pea varieties including Dun, Green (Organic), Speckled, Afila Tendril, Yellow, Thomas Laxton, Early Frosty, Yellow Sugar, and Snow (Dwarf Sugar Grey) develop very aggressive root systems. While they will grow on a reusable medium, their roots tangle deeply into the material, making cleanup extremely difficult and potentially damaging your medium.

For peas, we recommend using mesh trays without any grow medium for the easiest growing experience. If you do want to use a medium with peas, the 1.7mm large-hole silicone is the only silicone option we recommend for them, since the larger hole size accommodates their aggressive roots better than the standard 1.2mm. For a full walk-through, see our how to grow pea microgreens on various trays blog.

Seeds We've Tested Successfully With the Heat Mat Method

Very tiny seeds were originally thought to fall through the mesh, making them impractical for reusable grow mediums. However, one of our customers shared a method with us, and after extensive testing, we've confirmed that the heat mat method works for several extra-small seed varieties on our 1.2mm silicone reusable grow medium.

Confirmed successful on the 1.2mm silicone with heat mat method:

Amaranth Red Army
Amaranth Red Garnet
Amaranth Bicolor
Amaranth Glitter Mix
Celosia
Shiso

The Heat Mat Method: Use a seedling heat mat set to 75°F. Water the medium once, seed evenly, and keep the trays covered for a few days until germination. You might need to mist around day 3. After germination, follow normal growing steps. Some seeds will fall through the mesh, but the loss is minimal. Without the heat mat, these seeds may struggle to germinate evenly or fall through more readily.

Extra tiny seed varieties we still have not tested with the heat mat method: Red Veined Sorrel, Wasabina Mustard, and other extra-tiny varieties. This list will evolve as we continue testing.

Purple cabbage microgreens growing on On The Grow's reusable silicone grow medium

Seeds That Prefer Soil or Coco Coir

These varieties have specific germination requirements that reusable grow mediums don't satisfy well. For these crops, stick with soil or coco coir.

Beet Varieties: Detroit Dark Red (Conventional), Detroit Dark Red, Bulls Blood, and Rainbow Blend all prefer soil-based growing. Beets benefit from a 4 to 6 hour pre-soak.

Swiss Chard Varieties: Ruby Red, Rainbow Mixture, Pink Lipstick, Yellow, and Barese Dark Green Smooth Leaf perform better in soil or coco coir. Like beets, Swiss chard benefits from a 4 to 6 hour pre-soak.

Seed Mixes: Chard and Beet Rainbow Sprinkles Mix combines varieties that prefer traditional mediums.

Herbs and Other Varieties: Cilantro Slow Bolt, Cilantro Leisure Splits, Fennel Florence, Buckwheat, Borage, Nasturtium Jewel Mix, Nasturtium Alaska, and Marigold all germinate more reliably in soil or coco coir.

Choosing the Right Medium for Your Seeds

When selecting seeds for your reusable grow medium setup, consider starting with the varieties that work exceptionally well. Once you've mastered the basics of watering and harvesting with reliable seeds, you can experiment with more challenging varieties.

Our current flagship is the food-grade silicone reusable grow medium, which is third-party tested and FDA compliant per 21 CFR 177.2600, LFGB Tested & Compliant (1.2mm standard version). It's virgin food-grade platinum-cured silicone with a fiberglass mesh core, rated for 20 to 30+ growing cycles. We previously sold a stainless steel version, but we no longer sell the 10x20 stainless steel as of 2024 and are phasing out the remaining 10x10 and small sprouting tray sizes. The seed compatibility above applies to both versions.

For larger seeds like sunflower, peas, or melon, the 1.7mm large-hole silicone medium provides extra space for root development while preventing smaller seeds from falling through.

Tips for Success

Start with compatible seeds. Choose from our recommended list when you're learning the watering techniques required for reusable grow mediums. Broccoli and radish are the most forgiving for first-timers.

Match your medium to your seed size. Use the 1.2mm silicone for most varieties and the 1.7mm large-hole silicone for larger seeds like peas, sunflower, and wheatgrass.

Master your watering. The key difference between growing on soil versus reusable mediums is water management. Reusable mediums don't retain moisture the same way, so you'll need to develop a feel for proper hydration levels. We bottom-water with Ocean Solution 2-0-3 at 0.5 oz per gallon, pH balanced to 5.5 to 6.0, since reusable mediums are inert and contain no nutrients.

Never soak mucilaginous seeds. Basil, chia, flax, and arugula form a gel coating when wet. Spread these seeds DRY on the medium, then mist lightly on top.

Keep your medium clean. Proper cleaning and sanitization between grows extends the life of your reusable medium and prevents pathogen buildup. See our cleaning and sanitizing guide for the full process. Always use our Microgreen Medium Scraper to remove root debris before washing.

Frequently Asked Questions

What's the easiest microgreen variety to grow on a reusable medium?

Broccoli and radish are the most beginner-friendly. Both germinate quickly (1 to 2 days), are forgiving of small watering mistakes, finish in 7 to 10 days, and have clean root release at harvest. Start with our how to grow broccoli microgreens guide.

Can I grow peas on a reusable silicone grow medium?

You can, but we don't recommend it. Peas have aggressive root systems that tangle deeply into any medium, making cleanup very difficult. Peas perform best when grown directly on a bare mesh tray with no medium at all. If you do want to use a silicone medium for peas, the 1.7mm large-hole version handles their roots better than the 1.2mm standard.

Can amaranth actually grow on a reusable grow medium?

Yes, but you need a seedling heat mat set to 75°F during germination. Without the heat mat, the seeds may fall through the mesh or germinate unevenly. We've confirmed this method works for Amaranth Red Army, Red Garnet, Bicolor, Glitter Mix, plus Celosia and Shiso. Some seed loss through the mesh is normal, but it's minimal.

Do I need to use fertilizer with a reusable grow medium?

Yes. Reusable mediums are completely inert (contain zero nutrients), so liquid fertilizer is essential for healthy growth. We use Ocean Solution 2-0-3 at 0.5 oz per gallon, pH balanced to 5.5 to 6.0. Skipping fertilizer on a reusable medium typically results in slower growth, lighter harvests, paler color, and reduced nutritional density. Never add fertilizer to soil. Fertilizer is only for coco coir and reusable mediums.

Which is better, 1.2mm or 1.7mm silicone?

It depends on what you're growing. The 1.2mm standard silicone works for most microgreen varieties (broccoli, radish, kale, cabbage, mustard, sunflower, basil, arugula, and similar). The 1.7mm large-hole version is designed for larger seeds and aggressive root systems like peas, sunflower, and wheatgrass. If you grow primarily small to medium seeds, start with the 1.2mm. If you grow a lot of peas or sunflower, the 1.7mm is worth adding.

Why won't beets, Swiss chard, and cilantro grow well on a reusable medium?

These varieties have germination requirements that reusable mediums don't satisfy well. Beets and Swiss chard have hard seed coats that benefit from being nestled in a moisture-retaining medium like soil or coco coir. Cilantro has a long, slow germination period (often 14 to 21 days) and prefers the moisture stability of soil. Stick with soil or coco coir for these varieties.

Final Thoughts

Growing microgreens on reusable grow mediums offers significant environmental and economic benefits, but seed selection plays a crucial role in your success. By choosing compatible varieties and understanding the limitations of different seeds, you'll set yourself up for consistent, high-quality harvests.

Remember that our compatibility testing is ongoing. As we discover new techniques and test additional varieties, we update our recommendations. If you successfully grow a variety we haven't tested yet, we'd love to hear about your method.

Ready to start growing? Explore our complete selection of reusable grow mediums and find the right setup for your microgreen operation.

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Updated: May 2026

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